Data Sheet

ADP2389/ADP2390

Rev. 0 | Page 7 of 23

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Figure 4. Pin Configuration (Top View)

Table 4. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

SS

Soft Start Control. Connect a capacitor from the SS pin to GND to program the soft start time.

2

COMP

Error Amplifier Output. Connect an RC network from the COMP pin to GND.

3

FB

4

VREG

Output of the Internal 5 V Regulator. The control circuits are powered from this voltage. Place a 1 μF, X7R or

X5R ceramic capacitor between this pin and GND.

5

GND

Analog Ground.

6 to 11, 19, 20

SW

Switch Node. Connect this pin to an inductor.

12 to 18

PGND

Power Ground. Return of the low-side MOSFET.

21

BST

Supply Rail for the High-Side Gate Drive. Place a 0.1 μF, X7R or X5R capacitor between SW and BST.

22 to 26

PVIN

Power Input. Connect PVIN to the input power source and connect a bypass capacitor between this pin and

PGND.

27

VIN

Power Input for Control Circuitry. Bypass VIN to GND with a low equivalent series resistance (ESR) capacitor

as close to the device as possible. Connect VIN to PVIN directly.

28

EN

Precision Enable. Use an external resistor divider to set the turn on threshold. To enable the device

automatically, connect the EN pin to PVIN.

29

FTW

Fast Transient Response Window Setting. Connect a resistor between the FTW pin and GND to set the fast

transient response window.

30

PGOOD

Power-Good Output (Open-Drain). Connecting a 10 kΩ to 100 kΩ pull-up resistor from PGOOD to a pull-up

voltage is recommended.

31

ILIM

Current-Limit Threshold Setting. Connect a resistor from the ILIM pin to GND to program the current-limit

threshold.

32

RT

Frequency Setting. Connect a resistor between the RT pin and GND to program the switching frequency

between 200 kHz to 2.2 MHz.

33

EP, GND

Exposed GND Pad. The exposed GND pad must be soldered to a large, external, copper GND plane to reduce

thermal resistance.

34

EP, SW

Exposed SW Pad. The exposed SW pad must be connected to the SW pins by using short, wide traces, or

soldered to a large, external, copper SW plane to reduce thermal resistance.

33

GND

34

SW

ADP2389/ADP2390

TOP VIEW

(Not to Scale)

1

2

3

4

5

6

7

8

SS

COMP

FB

VREG

GND

SW

SW

SW

24

23

22

21

20

19

18

17

PVIN

PVIN

PVIN

BST

SW

SW

PGND

PGND

NOTES

1. THE EXPOSED GND PAD MUST BE SOLDERED TO A LARGE, EXTERNAL,

COPPER GND PLANE TO REDUCE THERMAL RESISTANCE.

2. THE EXPOSED SW PAD MUST BE CONNECTED TO THE SW PINS BY

USING SHORT, WIDE TRACES, OR SOLDERED TO A LARGE, EXTERNAL,

COPPER SW PLANE TO REDUCE THERMAL RESISTANCE.